1. Field of the Invention
This invention relates to a magnetic detection device for detecting magnetic ink printed on media, the device being applicable to, for instance, a valuable media processing machine to inspect the media as securities.
2. Description of the Related Art
This kind of magnetic detection device is equipped with a magnetic sensor and a conveying roller mechanism that are arranged opposing to each other with a gap between. Media are passed through the magnetic sensor and the conveying roller mechanism and printed magnetic inks are detected.
To detect magnetic ink, media are needed to pass through the magnetic detection device in contact with the surface of the magnetic sensor and conveyed while kept pushed against the surface of the magnetic sensor by conveying rollers.
Further, the magnetic sensor is statically installed and the conveying rollers are installed rotatably. The magnetic sensor and the conveying rollers are arranged with a certain gap between them so that they do not contact each other.
A gap between the surface of the magnetic sensor and the surfaces of the conveying rollers is adjusted by moving the conveying roller mechanism close to or far away from the surface of the magnetic sensor.
However, it was so far difficult to adjust a gap precisely and furthermore, a long time was needed because a gap was adjusted by loosening the fixing screw fixing the conveying roller mechanism at a specified position and then, moving the conveying roller mechanism directly.
Further, in the case of a conveying roller mechanism with many conveying rollers installed to a rotary shaft axially for pressing a wide area simultaneously, it was difficult to adjust gaps uniformly at axial points of the rotary shaft.